Such is cycling in 2012. This summer, Britain won its first Tour de France, with Bradley Wiggins topping the podium on the Champs Élysées – an event I scarcely expected to witness in my lifetime. Then, he won the Olympic time trial. If it was a disappointment that Team GB fought but failed to get Mark Cavendish gold in the Olympic road race, I'm still pinching myself every time I see a British rider (that is, Cav) wearing the rainbow jersey of the world champion all season.

And the result of all this glory? British Cycling, UK cyclesport's governing body, has set a new record membership. This means that a sport that, when I first took up bike-racing in my 20s, ranked somewhere between Tiddly-Winks and Shove-Ha'penny in popularity, has now almost pushed footy into the shade, at least for a few weeks in the FA's off-season.

So, cycling is a lot more popular. And suddenly, a lot of chaps – who might once have spent their middle years chasing a ball around some godforsaken suburban wasteland masquerading as a football pitch until a dodgy knee or persistent groin strain sidelined them – have discovered the joy of Lycra. There's a name for us; we are a demographic – as a BBC feature widely shared this week noted: "Rise of the Mamil (middle-aged men in Lycra)", by Dominic Casciani.

In short, if you got all enthused, dusted down your old bike, wriggled into a pair of Lycra shorts, bought a team jersey and went out for a ride, you are now officially a fool.

But Mamil: the clue is in the term "middle-aged", of course. We know what is really being said here. In fact, Casciani – a cyclist's name if ever I heard one – said it in his first line:

"Flashy sports cars are out, now no mid-life crisis is complete without a souped-up road bike."

In other words, we Mamils are pathetic creatures, cramming our spreading midriffs into unsightly spandex sports gear and spending unfeasible sums of money on custom-made carbon-fibre racing bikes. Then we jet off to the Alps or Pyrenees in order to live out a laughable fantasy that we, in some alternate universe, belong to the fraternity of demigods who ride bikes for a living.

Well, as a paid-up member of these noble "weekend warriors", I must object and speak up for the much-mocked Mamil. First, as midlife crises go, how benign is this? The worst of it is that you annoy your partner because you want a pasta meal and an early night on Saturday – on account of your early morning 60-mile Sunday training ride. (With other Mamils: we ride in a bunch – that's our collective noun.)

You get fit; your legs become firm and shapely; you lose a few pounds. Is that so terrible?

Admittedly, your partner may find your explanation for why you have started shaving your legs either baffling or implausible. Then again, you have a hard time believing your own BS on this issue. It's just what looks "pro", so it must be done.

But beside that issue, there's no substance abuse – unless you count a mild fixation with carbo-loading and disgusting sports drinks. Despite appearances to the contrary (rendezvous with strangers, an empty bed in the early morning, unaccountable foreign travel), there is no infidelity involved.

And compared to the old midlife crisis cliche of the sports car, how foolish and self-indulgent is a bike? OK, so your third or fourth bike might be considered foolish and self-indulgent – but only by people who don't understand these things. And at least a new Trek Madone is a lot easier to conceal than a bright red Alfa Romeo – both in the garage and on the credit card statement.

So, what's so bad about being a Mamil? Yes, we may be faintly ridiculous, but we're not rotters. Jackasses, perhaps, but not jerks. Society may label us and mock us – with the same sort of slighting acronym with which it likes to tag out-front women: Wag, Swoftie, Milf. But for me, the implicit derision of the label slips off my Lycra-clad back. I own my Mamilhood: I'm a middle-aged man in Lycra – and proud. And by the way, "Milf": that is so sexist. I know many a Mamil who has a perfect right to be considered a "Filf". You should see them in a pair of cycle shorts!